Add Copilot instructions for repository context

[Copilot]

Configures GitHub Copilot instructions per best practices to provide AI assistance with repository-specific context.

Changes

Created .github/copilot-instructions.md documenting:

• Architecture: Rush monorepo with core assertion library and Chai shim, multi-environment testing (node/browser/worker)
• Build system: Grunt + Rollup + TypeDoc pipeline, ES5/ES6 dual-target compilation
• Code conventions: ESLint rules (4-space indent, double quotes, ES5 compatibility), TypeScript ~5.2.2
• Testing patterns: Karma-based browser/worker tests, ts-mocha for node, cross-environment assertion examples
• Dependencies: Minimal external deps philosophy, version constraints for @nevware21/ts-utils and @nevware21/ts-async
• Common tasks: Adding assertions, updating dependencies, release process
• CI/CD: GitHub Actions matrix testing on Node 16/18/20, codecov integration

This provides Copilot with sufficient context about project structure, conventions, and workflows to offer better code suggestions.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• gh.io
  • Triggering command: curl -L -s REDACTED (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>✨ Set up Copilot instructions</issue_title>
<issue_description>Configure instructions for this repository as documented in Best practices for Copilot coding agent in your repository.

</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes ✨ Set up Copilot instructions #165

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[Copilot]

Pull Request Overview

This PR adds GitHub Copilot instructions to provide AI assistance with repository-specific context about the tripwire testing library project. The instructions document covers the monorepo structure, build system, coding conventions, and development workflows to help Copilot offer better code suggestions aligned with project standards.

• Comprehensive documentation of Rush monorepo architecture with core assertion library and Chai compatibility shim
• Detailed ESLint rules and TypeScript configuration (ES5/ES6 dual-target, ~5.2.2)
• Multi-environment testing workflows for node, browser, and web worker environments